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Marine permaculture could be a key climate change solution

Climate change can make you feel all is lost but solutions like kelp forests - which have been shown to quickly help restore a marine ecosystem - show there is a way forward, we just have to persuade those who hold the power to adopt them, writes Maddy Harland


A couple of years ago I had the surreal experience of attending a ‘do’ at Marlborough House, the home of the Secretary General of the Commonwealth, Baroness Patricia Scotland.

The ‘SG’, as she likes to be known, was hosting a Reverse Climate Change event, exploring the many effective ways we can not only reduce carbon (a.k.a greenhouse gases or GHGs) in the atmosphere, but draw it down and lock it up in the soil, biomass (forests, regenerative agriculture systems, even buildings and infrastructure) and in the oceans. She had invited a number of world-class visionaries to present their ideas to heads of state and commissioners from the Commonwealth nations, with Prince Charles, and others.

One of the speakers that day was the author and climate change activist, Paul Hawken … but before I launch into my story, I will set the scene with some sobering facts that I recently read in Burn: Using Fire to Cool the Earth by Albert Bates and Kathleen Draper. (Incidentally, this is a fascinating book about the many applications of biochar in regenerative agriculture, manufacturing, and construction that can be designed into a circular economy. More of this another time…)

In 2009, a conference called Four Degrees Beyond International Climate was held in Oxford: 140 scientists, government officials, NGOs and the private sector attended. They concluded that a 4C rise in global temperatures might be survivable by small, resilient and ingenious groups of humans like the Inuit or the Kuna but not by the majority of humanity.

Before we wonder who is going to make it, we need to ask how likely is a 4C temperature increase?

Patrick T. Brown and Ken Caldeira from the Department of Global Ecology, Carnegie Institution for Science, in California, USA wrote in the journal, Nature in 2017 that there is a 93% chance that the planet will be more than 4C warmer than now by 2100:

In particular, we find that the observationally informed warming projection for the end of the twenty-first century …  is about 15 per cent warmer (+0.5 degrees Celsius) … reported by the Intergovernmental Panel on Climate Change. Our results suggest that achieving any given global temperature stabilization target will require steeper greenhouse gas emissions reductions than previously calculated.

Feeling powerless

When most of us read statistics like these it can be devastating and make us feel powerless to do anything positive. And then there are people like Paul Hawken …

In 2001, Paul began asking climate and environmental experts whether they knew how to reverse climate change. He found that there was no research available to say what solutions would work the best.

So in 2013, he decided to gather together a team of academic research fellows – student and scholar volunteers from all over the world – to analyse the top 100 solutions.

That team assessed hundreds of pages of research and mathematical models and ranked the solutions by net costs, operational savings and benefits to society (between 2030 - 2050). They used carbon (CO2) as the ‘currency’ relative to other GHGs, like methane and nitrous oxide, and calculated them all relative to CO2. They calculated how many gigatons of carbon emissions a technology or behavioural change could save or indeed sequester (lock up). The gigatons saved is the total GHGs emission and you can read about the 100 solutions Here

Genuine sadness

One of the loves of my life is the sea. My earliest memories are of long drives to Dorset or Devon from London and that incredible experience of cresting a hill and seeing the sparkling waters beyond. It is still a moment of pure joy. So it is with genuine sadness that I read of collapsing marine ecosystems, endangered species of once common fish like Atlantic salmon and cod, eel and Bluefin tuna, and the fact that 90% of the world’s coral reefs will die by 2050 due to warming.

To indigenous people, these sentient creatures are our ‘relations’. We desperately need to make them all our relations in the West too. Only a sense of deep connection will change how we behave collectively.

One slide Paul showed at the Commonwealth event was not part of the 100 solutions but part of an addendum of future solutions: Marine Permaculture. He mentioned how Brian Von Herzen, once a systems engineering consultant, now devotes his life to reversing global warming by restoring the primary production of oceans, using kelp and other seaweeds. Primary production is the creation of organic compounds from carbon dioxide through photosynthesis. In other words, using a natural process like photosynthesis to create new growth, new life, to help regenerate our heating oceans.

Our oceans are in a dire state. For tens of millions of years, they have maintained a relatively stable acidity level but now they are saturated with carbon dioxide. Scientists now know that about half of the anthropogenic, or human-produced, CO2 has been absorbed by the oceans and relatively new research is finding that the introduction of massive amounts of CO2 into the seas is altering water chemistry, causing acidification, affecting the life cycles of many marine organisms, particularly those at the lower end of the food chain. Ocean deserts are rapidly expanding and ecosystems are collapsing as the waters warm and acidify.

Restoring marine life

Von Herzen wants to restore marine life in subtropical waters with thousands of new kelp forests—and he calls this marine permaculture.

The key technology is the building of marine permaculture arrays (MPAs). These are lightweight, latticed structures roughly half a square mile in size, submerged eight feet below sea level, to which kelp can attach. The MPAs have buoys attached to them and they rise and fall with the waves, powering pumps that bring up colder, nutrient-rich waters from far below.

The kelp soaks up the nutrients and grows, establishing a trophic pyramid rich in plant and animal life. This is exactly like planting a woodland; the trees create habitat for other species that naturally appear and take up residence. Like a permaculture woodland, the kelp forest is not just a nature reserve; it can also be harvested for food, fibre, animal feed, fertiliser and biofuels.

The kelp plants that are not consumed die off and drop down onto the seabed, sequestering carbon for centuries in the form of dissolved carbon and carbonates. Imagine, kelp forests sequestering billions of tons of carbon dioxide, while providing sensitively farmed products for the world.

Von Herzen describes how his MPAs can quickly change a marine ecosystem: “In just 57 hours after deployment, the system sparked plankton growth. Shortly thereafter, these blooms attracted various species of fish. Two weeks later, a 17-foot long (5m) whale shark was circling the area feeding on plankton that had started blooming.”

As large fish like shark and marine mammals like whales swim through oceans, they bring up cold water from depths, disrupting the warming surface water, which makes it more habitable for other species. They also leave blooms of their poo and the rich nutrients feeds plankton that then feed even more fish. Suddenly, we have what is called a trophic cascade, a condition or change in circumstances that kick-starts a dying ecosystem.

This makes my heart sing. This is what enables me to face the devastating reality of climate chaos. Now what we have to do is persuade the world that we do have many proven solutions to reverse climate change and that they can be linked together in circular economies that create habitat, upcycle waste, feed people and cool the planet.

Maddy Harland is the co-founder and editor of Permaculture magazine – earth care, people care and future care – and the author of Fertile Edges: regenerating land, culture & hope.

Image credit:  Whale Shark, Creative Commons - User:Zac Wolf (original), enhanced by User:madmax32


Suddenly, we have what is called a trophic cascade, a condition or change in circumstances that kick-starts a dying ecosystem

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